Only 34 pupils attend Ripple Primary School, near Deal, and the local education authority has said keeping it open is not financially viable.

BBC: NEWS | UK | England | Kent | Fight on for 'smallest' school

Mexico has one of the highest rates of pre-primary school enrolment among OECD countries, but only under half of students complete secondary education, according to an OECD report in 2012.

BBC: Mexico's Pena Nieto enacts major education reform

In 2004, for example, only 37.4% of primary school graduates made the transition from primary to secondary general education.

UNESCO: Family Basic Education (FABE)

Aid, too, could be better directed: only 15% of it is earmarked for education and health, and countries where fewest children go to primary school have had the biggest aid cuts this decade.

ECONOMIST: No school, no future

According to a recent study, the Functional Adult Literacy Programme (FALP) which endeavoured to promote youth and adult functional literacy, was only accessible to about 5% of the potential beneficiaries while only about 37.4% of children who completed primary school under the UPE programme were able to access secondary education.

UNESCO: Country Profile: Uganda